Not entirely, but just so you know, some women actually develope "temporary" diabetes while pregnant (I don't want you getting scared if it happens).
Either way if the father has then the doctors can run tests and monitor the baby to make sure everythings ok. They will probably suggest to each healthier and stay away from items with a high concentrate of carbohydrates.
Diabetes runs on my father's side of the family. My uncle doesn't have it, I don't have it neither do my sister or brother. It doesn't mean that later on it won't develope though. My father had check ups every year to make sure his sugar level was normal and last year, at 48, he developed it but he keeps it under control.
Your baby will probably not be born with diabetes but take the medicine the doctors give you to control your levels and get your child in the habit of getting yearly blood tests for safety's sake. Good luck with everything, don't worry about anything, and congrats :)
I have delt with both types of diabetes, it runs in my family.
Here is a great site about diabetes, whether you develope it while pregnant or even just to get some more information on diabetes...